Carburetor



March 1, 1966 J. T. BICKHAUS ETAL 3,237,926

GARBURETOR Filed Feb. 15, 1963 10/ INVENTORS a JAMES T. BICKHAUS Ii HAROLD A.CARLSON F IG. 7. BY

AGENT United States Patent 3,237,926 CARBURETOR James T. Bickhaus, Granite City, 11]., and Harold A. Carlson, Brentwood, Mo., assignors to ACF Industries, Incorporated, New York, N.Y., a corporation of New Jersey Filed Feb. 15, 1963, Ser. No. 258,869 3' Claims. 01. 261-16) This invention relates to carburetors for internal combustion engines, and more particularly to anti-icing systems for carburetors.

It will be understood that in cool humid weather there may be a tendency for ice to form in a carburetor, particularly when the engine is slowing down with closed throttle or when idling. Ice will often form on the throttle valve and on the inside of the mixture conduit of the carburetor as well as in the vicinity of the idle port of the carburetor. This is due to the cooling effect of expansion of the air/ fuel mixture, tending to cause moisture in the air to freeze. Icing may cause the engine to stall, due to the ice restricting the flow of air/ fuel mixture to the engine at idle, and is highly objectionable. Accordingly, among the several objects of this inventon may be noted the provision of anti-icing systems, which utilize air heated by the engine to heat the throttle valve and the wall of the mixture conduit of the carburetor in the vicinity of the idle port, and which are so constructed as to obtain increased utilization of the heated air thereby effectively to tend to prevent icing; and the provision of such systems in an economical manner. Other objects and features will be in part apparent andin partpointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings in which several of various possible embodiments of the invention are illustrated,

FIG. 1 is a view in side elevation of the engine of an automotive vehicle equipped with a carburetor of this invention;

FIG. 2 is an enlarged view in elevation of the carburetor with parts broken away and shown in section;

FIG. 3 is a fragmentary section taken generally on line 3-3 of FIG. 2;

FIG. 4 is a section of the automatic choke control taken on lines 44 of FIG. 3;

FIG. 5 is an enlarged fragmentary section showing the lower portion of the carburetor shown in FIG. 2 viewed from the opposite side;

FIG. 6 is a section taken on line 6-6 of FIG. 5; and

FIG. 7 is an enlarged fragmentary section showing another embodiment.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawmgs.

Referring now to the drawings, there is indicated at 1 in FIG. 1 the internal combustion engine of an automotive vehicle 2. At 3 is indicated a carburetor of this invention which, as shown in FIG. 2, comprises a main body 5 formed to provide a vertical mixture conduit 7 and a fuel bowl 9, a bowl cover 11 having an air horn 12 for mixture conduit 7, and a throttle body 13 having a throttle bore 15 coaxial with and in continuation of the mixture conduit. A float valve for controlling flow of fuel to the fuel bowl is indicated at 17. A throttle shaft 19 extends across the throttle bore and carries a throttle valve or plate 21, the configuration of which will be described hereinafter.

A boost venturi 23 is provided in the mixture conduit.

3,237,926 Patented Mar. 1, 1966 A so-called high speed fuel system for the carburetor is generally indicated at 25, and comprises a metering jet 27 through which fuel may flowfrom the fuel bowl under control of a metering rod 29 to a passage 31 for delivery through a fuel nozzle 33 into the boost venturi.

A carburetor idle system is shown to comprise a passage 35 leading upwardly from passage 31 and having an orifice tube 37 communicating with a passage 39 leading to a vertically aligned idle port 41 and an idle adjustment port 43 having an idle adjusting screw 45.

Extending across the air horn is a choke valve shaft 47 carrying a choke valve 49. One end of shaft 47 projects into a choke control housing 51 having a partition 53 and a cover 55 secured thereon by means of screws 57. A bifurcated stud 59 is fixed 0n the cover to which is secured the inner end of a spirally wound bimetallic thermostat 61, the outer end of the thermostat engaging the end of a crank 63, which projects through an arcuate slot 67 in the partition 53. A cylinder 69 is provided in housing 51 for receiving a piston 71 connected to the crank 63 by a link 73. A bypass groove 75 is formed in the wall of cylinder 69.

In accordance with this invention, a suction passage 77 having a first generallyvertical portion 79 and a second generally horizontal portion 81, leads from cylinder 69 below piston 71 and groove 75 to a suction port 83 opening into the mixture conduit at a point adjacent a marginal portion 85 of the throttle valve 21 when the latter is in idle position. A tubular insulation liner 87 is inserted in the vertical portion 79 of passage 77. Throttle valve 21 has a hemispherical slot 89 in its periphery ex tending across the marginal portion 85. An opening 91 is provided in the lower portion of the slotted margin 85 of throttle valve 21'. When the throttle valve 21 is in its idle position, suction port 83 registers with slot 89, and idle port 41 and slot 89 are in partial registration. Heated air is piped from a stove 93 on the exhaust manifold 95 of the engine 1 to the choke control housing via a pipe 97 as shown in FIG. 1.

Operation of the system is as follows:

When the engine is operating at an idle speed, because of manifold vacuum, heated air is drawn to the choke control housing 51 via pipe 97. Choke 49 is open and piston 71 is in its retracted FIG. 3 position. The throttle valve 21 is in its idle position, as shown in FIGS. 2, 3, 5 and 6. Intake manifold suction draws heated air from the choke control housing through the piston bypass groove 75 into the portion 79 of suction passage 77. The insulation liner 87 reduces the transfer of heat to the body 5 as the heated air flows through portion 79 and retains the air at a higher temperature. The heated air is directed, by port 83 into the throttle slot 89 where it internally contacts marginal portion 85 of the throttle valve. The heated air sweeps through slot 89 laterally across the portion of the throttle valve adjacent the idle port. This effectively prevents icing. Fuel is simultaneously sucked into slot 89 from idle port 41, where it is mixed with the heated air from port 83. Air from the mixture conduit upstream of the throttle valve is drawn into the idle port 41 above the marginal throttle portion 85 and mixes with the idle fuel. The air/fuel mixture is discharged from slot 89 through opening 91.

While in FIG. 3 there is shown the use of insulation liner 87 to reduce the transfer of heat to the main body from the air flowing through the suction passage, this liner need not always be used since the use of the slotted throttle valve itself effectively prevents icing.

A modified form of this invention is illustrated in FIG. 7. In this embodiment, a nonslotted throttle valve, such as indicated at 101, is utilized. The portion 79 of passage 77 is provided with an insulation liner 87 in the same manner as shown in FIG. 3. The second portion of passage 77, indicated at 103 in FIG. 7, is upwardly inclined to direct air upwardly against the downstream side of the marginal portion of the throttle valve 101 adjacent the idle port when the latter is in its idle position. In this form of the invention, the insulation liner appears to be essential effectively to attain the desired anti-icing results.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above con structions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. A carburetor for an internal combustion engine, comprising a body having a fuel and air mixing conduit therein, an air inlet in said conduit, said carburetor having means defining an idle system including an idle port opening into said mixture conduit, a throttle plate of general circular form in said mixture conduit adapted to occupy an idle position in which a marginal edge portion of the throttle plate is adjacent said idle port, said throttle plate having a slot in its periphery extending across the marginal edge portion adjacent to said idle port, thereby forming a slot having a hemispherical shape, said body having a passage receiving heated air at one end and opening at its other end into the mixture conduit, said other end of said passage being disposed in registration with said slot when said throttle plate is in the idle position to direct heated air from said passage into said slot, said slot in said throttle plate being disposed in registration with said idle port when said throttle plate is in the idle position, whereby fuel will flow from said idle port into said slot, said throttle plate including outlet means connected to said slot for discharging heated air and fuel which passes therethrough, said outlet means being in the lower portion of said throttle plate and facing in a downstream direction in relation to said mixture conduit.

2. A carburetor as set forth in claim 1 including means for insulating at least a portion of said passage to reduce transfer of heat to said body from the heated air flowing through said passage.

3. A carburetor as set forth in claim 2 having a choke in said mixture conduit upstream from the throttle, control means for the choke, a housing for said control means adapted to receive said heated air, said passage having its said one end in communication with said housing for flow of air from the housing into said one end of the passage, and said passage having a first portion extending in downstream direction with relation to the mixture conduit through said body and having a second portion extending laterally from the downstream end of said first portion to the mixture conduit, said insulating means being constituted by tubular insulation liner means inserted in said first portion of said passage.

References Cited by the Examiner UNITED STATES PATENTS 2,393,760 1/ 1946 Eberhardt 261 2,693,175 11/1954 Hickock et al 123-122 2,711,883 6/1955 Reeves.

2,719,519 10/1955 Sutton 261-16 2,957,685 10/1960 Cook et a1 261- FOREIGN PATENTS 100,956 6/ 1917 Great Britain. 343,466 2/1931 Great Britain.

r HARRY B. THORNTON, Primary Examiner.

RONALD R. WEAVER, Examiner. 

1. A CARBURETOR FOR AN INTERNAL COMBUSTION ENGINE, COMPRISING A BODY HAVING A FUEL AND AIR MIXING CONDUIT THEREIN, AN AIR INLET IN SAID CONDUIT, SAID CARBURETOR HAVING MEANS DEFINING AN IDLE SYSTEM INCLUDING AN IDLE PORT OPENING INTO SAID MIXTURE CONDUIT, A THROTTLE PLATE OF GENERAL CIRCULAR FORM IN SAID MIXTURE CONDUIT ADAPTED TO OCCUPY AN IDLE POSITION IN WHICH A MARGINAL EDGE PORTION OF THE THROTTLE PLATE IS ADJACENT SAID IDLE PORT, SAID THROTTLE PLATE HAVING A SLOT IN ITS PERIPHERY EXTENDING ACROSS THE MARGINAL EDGE PORTION ADJACENT TO SAID IDLE PORT, THEREBY FORMING A SLOT HAVING A HEMISPHERICAL SHAPE, SAID BODY HAVING A PASSAGE RECEIVING HEATED AIR AT ONE END AND OPENING AT ITS OTHER END INTO THE MIXTURE CONDUIT, SAID OTHER END OF SAID PASSAGE BEING DISPOSED IN REGISTRATION WITH SAID FLOT WHEN SAID THROTTLE PLATE IS IN THE IDLE POSTION TO DIRECT HEATED AIR FROM SAID PASSAGE INTO SAID SLOT, SAID SLOT IN SAID THROTTLE PLATE BEING DISPOSED IN REGISTRATION WITH SAID IDLE PORT WHEN SAID THROTTLE PLATE IS IN THE IDLE POSITION, WHEREBY FUEL WILL FLOW FROM SAID IDLE PORT INTO SAID SLOT, SAID THROTTLE PLATE INCLUDING OUTLET MEANS CONNECTED TO SAID SLOT FOR DISCHARGING HEATED AIR AND FUEL WHICH PASSES THERETHROUGH, SAID OUTLET MEANS BEING IN THE LOWER PORTION OF SAID THROTTLE PLATE AND FACING IN A DOWNSTREAM DIRECTION IN RELATION TO SAID MIXTURE CONDUIT. 